The present invention relates to a coding method for high-capacity storage medium and the decoding means for the same, more particular, to a coding method for CD-Recordable (CD-R), CD-Rewritable (CD-RW) to enhance the storage capacity thereof while being compatible with existing system and the decoding means for the same.
As the rapid development of computer software and raising of CPU speed, the storage of conventional storage means is not enough. Although advanced storage mediums such as DVD is developed to overcome this problem, those medium are not mature to satisfy user""s need. Therefore, it is an important issue to enhance the storage capacity of the existing CD-R,CD-RW.
FIGS. 1-6 show the conventional coding method for CD, wherein FIG. 1 shows the ATIP (absolute time in pre-groove) coding for the conventional CD-R/CD-RW. The guiding groove is a trench with sinusoid-like wobble in a specific frequency and the information such as timing data and the disk format are established with respect to the frequency as a carrier frequency. As shown in FIG. 1, the ATIP coding begins from the program area and extends outward. The program area begins at t4 (00:00:00), which also records the end time in lead-in area (99:59:74). The time t5 indicates the begin time of the lead-out area of the last data and is determined by ATIP coding. As to the inward direction, the time t3 indicates the begin time of the lead-in area and is determined by ATIP coding. More inward is the time t2 for begin time of PMA (t3-00:13:25) and the time t1 for the begin time of PCA(t3-00:35:65). In other word, the data structure of CD are, from inner side, PCA, PMA, lead-in area, program area and lead-out area. The recording time is counted from time t4 and extends outward and inward from the lead-in time defined by ATIP.
FIG. 2 shows the ATIP data format in the lead-in area for conventional CD-R/CD-RW. The BCD expression for the minute, second and frame in ATIP data format are as follows:
minute: 2 binary BCD (M1 . . . M4 and M5 . . . M8), the MSBit (M1) in 5th location;
second: 2 binary BCD (S1 . . . S4 and S5 . . . S8), the MSBit (S1) in 13th location;
frame: 2 binary BCD (F1 . . . F4 and F5 . . . F8), the MSBit (F1) in 21st location;
and when M1S1F1
=000, the time code of the program area and the lead-out area;
=100, time code of PCA (power correction area), PMA (program manage area) and the lead-in area;
=101, special information 1 for writing power, reference rotation speed, application code and disk format;
=110, special information 2 for begin time of lead-in area;
=111, special information 3 for the possible begin time of the last last-out area;
=001, additional information 1 undefined in CD-R and for speed range, optimal control parameter and erasing power in high/low recording speed in CD-RW;
=010, additional information 2 undefined in CD-R and for writing power in high/low recording speed, optimal control parameter and erasing power in high/low recording speed in CD-RW;
=011, additional information 3, undefined in CD-R and CD-RW.
FIG. 3 shows the ATIP coding in the lead-in area of the conventional CD-R. One ATIP coding frame encoded with special information, followed by nine ATIP frame encoded with timecode information, such as follows, a special information 1 (3 bytes) followed by 9 normal time code, a special information 2, 9 normal time code, a special information 3, and 9 normal time code. In order, the three special information with 27 time code cyclically appear in the lead-in area.
FIG. 4 shows partial data in special information 1 of the ATIP coding in the conventional CD-R. The area is defined by M1S1F1=101, and the usage of the additional information is defined by the frame coding area A1, A2 and A3. In existing CD-R, the additional information are undefined, and in CD-RW, the additional information 1 and 2 are defined and the additional information 3 is undefined.
FIG. 5 shows the data format in special information 2 of the ATIP coding in the conventional CD-R. The area is defined by M1S1F1=110 and defines the begin time of the lead-in area.
FIG. 6 shows the data format in special information 3 of the ATIP coding in the conventional CD-R. The area is defined by M1S1F1=111 and defines the possible begin time of the out most lead-out area. When CD-R/CD-RW reads the ATIP data of CD, the M1S1F1 of the special information 3 is interpreted as 000. Therefore, in the scheme of BCD coding, the maximum recordable minute is 111 1001 (79 minutes), the maximum recordable second is 110 1001 (59 seconds), and the maximum recordable frame is 111 0100 (74 frames) with 7 bits. In other word, the data length for existing CD-R/CD-RW is only 79 minutes and 59 seconds and 74 frames.
From above description, due to the limitation of BCD code, the storage capacity of the conventional CD is limited to about 80 minutes.
In general, the possible ways for increasing storage capacity are: (1) more efficient data coding, (2) reduce pit length and track pitch, (3) shorter wavelength, (4) larger numeral aperture, (5) multi-layer structure.
It is the object of the present invention to provide a coding method for high-capacity storage medium to increase the storage length to 100 minutes and the decoding means for the same.